I. Field of the Invention
The present invention relates to orotracheal intubation guides and more particularly to blind intubation guides for insertion of an orotracheal tube into a patient""s trachea, especially in the case of patients having a shallow throat.
II. Description of Prior Art
When a patient stops breathing, it is imperative that effective ventilation be instituted as soon as possible. Ventilation is best accomplished by forcing air through an orotracheal tube inserted through the mouth and laryngeal opening and into the trachea. A blade laryngoscope is commonly employed to provide such insertion. But the blade laryngoscope can be slow and difficult to use. The blade laryngoscope further requires manual visualization of the vocal cords so as to facilitate insertion of the tube. Use of blade laryngoscopes often results in dental and airway trauma and accidental insertion of the tube into the esophagus instead of the trachea. Such misintubation, if not quickly recognized and corrected, may have fatal consequences.
Blind intubation guides have been developed as an alternative to blade laryngoscopes. The goal of blind intubation guides is to eliminate the need for visualization of the vocal cords, and to reduce the risk of trauma and injury to patients which occurs with the use of blade laryngoscopes. I have developed several blind intubation guides which not only minimize such injury and trauma, but also substantially reduce the risk of misintubation. Such advantageous blind intubation guides are described in my U.S. Pat. Nos. 5,339,805 and 5,743,254, the disclosures of which are incorporated herein in their entirety.
The guides of my ""805 and ""254 patents have an elongated aft portion or member in which the orotracheal tube is mounted. The distal end of the aft member includes a support portion depending therefrom and designed to fit against the back of the patient""s tongue in or above the valleculae and in front of the epiglottis. The underside of the aft member may function as a tongue-depressor to hold the tongue down against the floor of the mouth. The guides further include a guide wall connected to the aft member and spaced forwardly of the support portion. The guide wall is designed to be positioned at the back of the throat to provide a bearing surface which directs the orotracheal tube downward into the laryngeal opening and trachea when the support portion is properly seated behind the tongue. To avoid snagging of the epiglottis by the tube and/or the tendency of the epiglottis to block the glottic opening, the guide may be provided with a spout extending from the aft member and towards the guide wall as described in my ""254 patent.
With the guides of my prior patents, intubation may thus be accomplished more reliably, and without substantial risk of trauma or misintubation as often occurred with blade laryngoscopes and other blind intubation guides. The guides of my prior patents are believed to accommodate most throat depths. In some instances, however, the throat may be very shallow such that the space between the back of the patient""s tongue and the rear wall of the throat is limited. In these cases, the guide wall can impact the rear wall of the throat preventing the support member from being advanced into the retroglossal space, i.e., the space behind the tongue. As a result, the guide cannot be properly seated therein, and the guide wall may not be properly aligned to direct the tube into the larynx. If the guide is simply made smaller to accommodate the shallow throat, then there may not be sufficient space between the guide wall and support member to pass the tube therethrough and into the larynx.
The present invention provides an improved blind intubation guide which overcomes the problems encountered in shallow throat situations. To this end, and in accordance with the principles of the present invention, the guide wall of the intubation guide is pivotally mounted to the aft member so that as the guide wall impacts against the rear wall of the throat, it can pivot so as to thereby decrease the spacing between the guide wall and the support member, from the normally desired spacing for a tube to fit through, to a lesser spacing as necessary to allow both the guide wall and the support member to fit simultaneously in the back of the throat and into the retroglossal space. With the guide wall thus pivoted, the support member can be advanced further into the throat so as to be placed behind the back of the tongue. Subsequent forward traction against the back of the tongue by the support member displaces the tongue forwardly thereby enlarging the space behind the tongue so that it is sufficient for normal placement of the guide wall and support member. With forward traction of the tongue by the support member, the guide wall is released from against the rear wall of the throat. The guide wall is thus enabled to pivot or be pivoted back toward its original position. The original space between the guide wall and the support member is thus reopened to allow the tube to pass therethrough and to allow the guide wall to achieve the desired alignment with the larynx. The tube, normally mounted to the aft member and the guide wall, is resilient and may be utilized to cause the guide wall to pivot back toward its original position as traction is applied to the back of the tongue.
The guide wall may be rigidly affixed to a side arm that is pivotally mounted to the aft member. The arm may include a mounting post member that is rotatably received in a post receiving channel formed in the aft member, such as in the support member near the upper end thereof. Stop structure may also be provided in the aft member and the side arm to limit the range of pivoting of the guide wall relative to the aft member.
The guide may also advantageously include a spout as taught in my ""254 patent. In accordance with a further aspect of the present invention, the spout is adapted to yield by flexing or deforming in response to pressure exerted by or through the tube. To that end, as the guide wall pivots towards the support member, the orotracheal tube mounted in the guide will be pushed against the spout by the guide wall and will cause the spout to yield by flexing or deforming. Yielding of the spout to pressure from the tube will prevent the tube from becoming unduly bent by or around the spout in a manner that could damage the tube or an instrument such as a fiberoptic bundle contained therein. As forward traction is applied by the support member to the back of the tongue, the pressure of the guide wall against the tube and the resulting pressure of the tube against the spout are simultaneously released. The spout is advantageously resilient such that the spout will flex back toward its original form and position. As the spout returns to its original pre-flexed form and position, it pushes the tube against the guide wall, causing the guide wall to pivot back toward its original pre-pivoted position.
By virtue of the foregoing, there are thus provided improvements to blind intubation guides that have the advantages of my prior patented blind intubation guides but which can readily accomodate shallow throats. These and other objects and advantages of the present invention shall be made apparent from the accompanying drawings and the description thereof.